PPPL-3135 is available in pdf or postscript formats.
Alpha Power Channeling with Two Waves
Authors: N.J. Fisch and M.C. Herrmann
The complete channeling of energy from alpha particles is likely to be realized only through the excitation of a variety of waves, rather than by one wave alone. While one wave constrains more firmly the direction of the energy transfer, the necessary wave characteristics are far more easily achieved through a combination of waves, even at the expense of less restrictive motion of the a -particles.